Hello all,
I have postfix configured and running, but its running as an open relay.
I believe i have narrowed it down to what it is but i need help to fix it.
Let me give you a gist of my setup.
ISP - > Netscreen firewall -> mapped public IP to internal IP mail server. The netscreen firewall acts as the gateway for LAN PC's and also the mail server.
When looking at logs i see this
Code:
Jul 18 15:14:50 mailsrvr amavis[17516]: (17516-13) Passed CLEAN, [192.168.1.90] [192.168.1.90] <user@example.com> -> <user@example2.com>, Message-ID: <CAO1B_7RrswzKDQ5cVhsZm-cbYR9vLZa0w-O5LWaUOP+_7yt6ww@example.com>, mail_id: LxfwSp87DHwG, Hits: -, size: 488350, queued_as: C7FAB1063AF9, 887 ms
Jul 18 15:14:50 mailsrvr postfix/smtp[18296]: 0D15A1062297: to=<user@example2.com>, relay=127.0.0.1[127.0.0.1]:10024, delay=4.1, delays=3.2/0.02/0.01/0.89, dsn=2.0.0, status=sent (250 2.0.0 Ok, id=17516-13, from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as C7FAB1063AF9)
In my postfix main.cf i have
mynetworks = 127.0.0.0/8,192.168.1.0/24
I have permit_mynetworks in my config.
So the gateway of 192.168.1.90 falls into the mynetworks , so its allowed to pass thru, so i believe thats whats causing it to be an open relay mailserver.
When i take away 192.168.1.0/24 its no longer an open relay, but i can no longer receive any incoming emails. I get 554 5.7.1 Client host rejected: cannot find your hostname, [192.168.1.90]
I attached my main.cf below
Code:
smtpd_banner = $myhostname ESMTP
biff = no
# appending .domain is the MUA's job.
append_dot_mydomain = no
# Uncomment the next line to generate "delayed mail" warnings
# TLS parameters
#smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
#smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
#smtpd_use_tls=yes
#smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
#smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache#delay_warning_time = 4h
readme_directory = no
# TLS parameters
smtpd_tls_cert_file=/etc/ssl/certs/dovecot.pem
smtpd_tls_key_file=/etc/ssl/private/dovecot.pem
smtpd_tls_security_level = may
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
#smtp_tls_per_site = /etc/postfix/tls_per_site
smtpd_tls_CAfile = /etc/postfix/CAcert.pem
# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.
myhostname = mailsrvr.example.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = $myhostname
mydomain = example.com
#myorigin = $mydomain
mynetworks = 127.0.0.0/8,192.168.1.0/24
mailbox_command = procmail -a "$EXTENSION"
mailbox_size_limit = 0
message_size_limit = 31457280
virtual_mailbox_limit = 31457280
recipient_delimiter = +
inet_interfaces = all
virtual_mailbox_domains = mysql:/etc/postfix/mysql-virtual-mailbox-domains.cf
virtual_mailbox_maps = mysql:/etc/postfix/mysql-virtual-mailbox-maps.cf
virtual_alias_maps = mysql:/etc/postfix/mysql-virtual-alias-maps.cf,mysql:/etc/postfix/mysql-email2email.cf
virtual_transport = dovecot
dovecot_destination_recipient_limit = 1
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
broken_sasl_auth_clients = yes
smtp_tls_per_site = hash:/etc/postfix/tls_per_site
show_user_unknown_table_name = no
sender_bcc_maps = hash:/etc/postfix/bcc_maps
recipient_bcc_maps = hash:/etc/postfix/bcc_maps
smtpd_helo_required = yes
strict_rfc821_envelopes = yes
smtpd_delay_reject = no
disable_vrfy_command = yes
unknown_address_reject_code = 554
unknown_hostname_reject_code = 554
unknown_client_reject_code = 554
header_checks = regexp:/etc/postfix/header_checks
body_checks = regexp:/etc/postfix/body_checks
smtpd_relay_restrictions = permit_mynetworks,
permit_sasl_authenticated,
reject_unauth_destination
smtpd_client_restrictions = permit_mynetworks,
reject_invalid_hostname,
reject_rbl_client b.barracudacentral.org,
reject_unknown_client,
permit
smtpd_helo_restrictions = permit_mynetworks,
check_helo_access hash:/etc/postfix/helo_client_exceptions,
permit_sasl_authenticated,
reject_unauth_pipelining,
reject_non_fqdn_helo_hostname,
reject_invalid_helo_hostname,
reject_non_fqdn_hostname,
reject_invalid_hostname,
warn_if_reject reject_unknown_hostname,
permit
smtpd_recipient_restrictions = check_sender_access hash:/etc/postfix/access,
check_client_access hash:/etc/postfix/access,
check_client_access cidr:/etc/postfix/access2.cidr,
permit_sasl_authenticated,
reject_non_fqdn_recipient,
# reject_non_fqdn_hostname,
reject_invalid_hostname,
permit_mynetworks,
reject_unauth_pipelining,
reject_unknown_sender_domain,
reject_unknown_recipient_domain,
reject_unauth_destination,
reject_unknown_client,
permit
smtpd_sender_restrictions = permit_mynetworks,
reject_non_fqdn_sender,
reject_unknown_sender_domain,
reject_unknown_address
smtpd_etrn_restrictions = permit_mynetworks,
reject
smtpd_data_restrictions = reject_unauth_pipelining,
reject_multi_recipient_bounce,
permit
content_filter = smtp-amavis:[127.0.0.1]:10024
receive_override_options = no_address_mappings
Thank you!.
